1. Field of the Invention
This invention relates to digging and levelling apparatus such as draglines, backhoes, front-end loaders and like equipment and more particularly, to a tooth assembly for mounting on the tooth horns of dragline buckets, backhoe shovels and front-end loader excavation or levelling equipment and engaging the material to be excavated or levelled. In a preferred embodiment, each tooth assembly is characterized by a wedge-shaped adapter which mounts directly on the tooth horn of the bucket, shovel or alternative digging or scraping mechanism of the operation equipment. A wedge-shaped tooth point is frontally seated on and bolted to a pair of inserts provided in cavities in the extending end of the adapter for engaging the material to be excavated or levelled. In a second preferred embodiment, a pair of wear caps transversely encapsulate and are bolted to that portion of the adapter which projects between the tooth point and the tooth horn, for extending the life of the tooth assembly during the excavating or levelling operation.
One of the problems which is inherent in excavation and levelling operations using heavy equipment such as draglines, backhoes, front-end loaders and similar equipment, is that of rapidly wearing the equipment teeth during the excavation or levelling operation. This problem is exacerbated under circumstances where the material to be excavated contains rocks, sand, concrete or other hard or abrasive particles which rapidly wear the bucket or shovel teeth and require expensive, periodic retrofits or replacement of the bucket or shovel. Accordingly, it is customary in the industry to provide removable excavating teeth which mount on adapters positioned on shaped, spaced tooth horns provided in the bucket, shovel or other material-moving apparatus, which teeth are typically attached to the tooth adapter using pins or other techniques, for removal due to wear. A problem associated with removing these teeth due to periodic wear is the difficulty of driving retaining pins or the like from registering apertures in the teeth and tooth adapters to remove and replace the teeth. Typically, this operation is effected using a large hammer, wherein the pins are manually driven from the teeth and tooth adapter, a procedure which requires considerable effort and is costly, due to the labor involved.
2. Description of the Prior Art
My U.S. Pat. No. 5,172,501, dated Dec. 22, 1992, details a tooth assembly for mounting on the tooth horns of excavating or levelling apparatus buckets, shovels or alternative digging mechanisms. The tooth assembly includes a wedge-shaped adapter shaped for seating on the tooth horn, a tooth point transversely slidably engaging and bolted or otherwise locked to the adapter for engagement of the material to be excavated and top and bottom wear caps, also transversely slidably engaging and bolted to the adaptor adjacent to the tooth point, for extending the life of the tooth assembly in the excavating or levelling operation. Other patents which are pertinent to the tooth assembly in the captioned application include U.S. Pat. No. 1,216,290, dated Feb. 20, 1917, to N. M. Dixon, which details an "Excavator Tooth". The excavator tooth includes a point having equal diversion arms equipped with inwardly-extending projections at their free ends and a base provided with a projection adapted to enter and fill the space between the arms and having edge recesses adapted to receive the projections and prevent relative longitudinal movement of the parts. The excavator tooth is reversible on the base for alternately presenting opposite edges of the tooth to wear. U.S. Pat. No. 1,419,047, dated Jun. 6, 1922, to G. R. Hanks, et al, includes a point-carrying element for a tooth member. The point-carrying element includes an upper and lower bearing surface transversely slotted and fitted with slide slots, with a reversible point having panels for slidable engagement with the transversely slotted portions and further including a side bar adapted to either of the side slots. U.S. Pat. No. 3,839,805, dated Oct. 8, 1974, to V. A. Stepe, details an "Open Side Ground-Engaging Tip" for mounting an adaptor on the cutting edge of an excavator bucket. The tip includes a wedge-shaped body which includes the wear part of the point and a rearwardly-extending strap at the top and bottom of the body. The straps diverge from the open side, generally U-shaped opening, for reception of the nose of the adaptor. Each strap has a key which extends laterally of the strap near the rear of the strap and the keys project normal to the straps and engage respective keyways located in the adaptor. U.S. Pat. No. 3,982,339, dated Sep. 28, 1976, to L. Nilsson, details a "Reversible Slide-On Digger Tooth With Easy Removal Arrangement". The tooth is designed to mount on a loading or excavating bucket and includes a support member adapted for connection to the edge of the bucket and a replaceable, wedge-shaped slide-on cap. The front portion of the support member is inclined with respect to the rear portion and the rear portion can be connected to the bucket in either of two positions, 180 degrees apart, so that the front portion and the slide-on cap can be disposed in either of two corresponding portions. U.S. Pat. No. 4,587,751, dated May 13, 1986, to Kay Sjogren, et al, details a "Wear Cap Style Excavating Tooth". The excavating tooth assembly includes a relatively elongated adapter equipped with a point at the digging end and at least one wear cap normally held in place by the point and further including lock means in the adapter to prevent dislodging of the wear cap. U.S. Pat. No. 4,716,667, dated Jan. 5, 1988, to Wesley E. Martin, details an "Excavating Tooth and Wear Cap Assembly". The assembly is designed such that the front pin which interconnects the replaceable point to the adapter nose is protected from undesirable deformation by interlocking, stabilizing lugs and grooves formed respectively, on the wear cap and adapter base portions of the assembly. Cooperation between these lugs and grooves prevents earth forces from driving the wear cap portion of the assembly forwardly along the adaptor base into the point and thereby causing the point to deform the connection pin. Field installation of a lower wear cap portion of the assembly is facilitated by cooperating support lugs on the wear cap and shoulders of the adapter, which, together with a pivotal interconnection between the adapter and wear cap, permit the lower wear cap to be hung from the adapter in a temporary support position until the point can be installed and interconnected to the wear cap to complete the assembly.
It is an object of this invention to provide a tooth assembly for mounting on buckets, shovels or other digging mechanisms in excavating or levelling apparatus, which tooth assembly is characterized by an adapter for removably mounting on each tooth horn of the excavating apparatus bucket, shovel or alternative excavating implement, a tooth point bolted to the tapered front end of the adapter by means of a shaped insert located in each of two cavities provided in each side of the adapter and, in one embodiment, a pair of wear caps bolted to opposite sides of the adapter between the tooth point and the tooth horn.
Another object of this invention is to provide a tooth assembly for mounting on each of the teeth of an excavating or levelling apparatus bucket, shovel or alternative digging implement, which tooth assembly includes a wedge-shaped, transversely-slotted adapter for mounting on the tooth horn of the excavating apparatus, a pair of shaped inserts provided in insert cavities located in opposite sides of the adapter and a wedge-shaped tooth point fitted with tooth point bolt openings for frontally mounting on the adaptor, receiving tooth point bolts threaded in the inserts and removably fitting the tooth point to the adapter. In a preferred embodiment top and bottom wear caps are provided, each fitted with transverse ribs adapted for engaging corresponding grooves or slots provided in the adapter, for transversely mounting the wear caps on opposite sides of the adapter rearwardly of the tooth point to facilitate extended wear of the tooth assembly during excavating or levelling operations.
A still further object of this invention is to provide a tooth assembly for mounting on the conventional tooth horn of individual teeth in the bucket or shovel of various excavating apparatus, which tooth assembly includes a transversely slotted, wedge-shaped adapter having a lock opening in the top for securing the adapter to the tooth horn, a pair of tapered insert cavities for removably receiving correspondingly tapered, internally-threaded inserts, a pair of L-shaped wear caps, each fitted with parallel ribs for engaging the corresponding transversely-oriented slots in the adapter, a pair of wear cap bolts for securing the wear caps to the adapter and a tooth point, fitted with a pair of bolt openings for receiving a pair of tooth point bolts which thread into the inserts for removably securing the tooth point to the adaptor forward of the wear caps.